Is it permissible for a government employee to engage in trade that does not affect his work, even though it is officially prohibited in Saudi Arabia, and is the money earned from it lawful or unlawful?

If a government employee is stipulated not to engage in trade, or if their commercial work affects their job performance, then they are not permitted to trade. However, if this is not stipulated and they have spare time beyond their official work, there is no objection to engaging in trade.